Wastewater

“The City of Hutchinson’s Wastewater department shall strive to provide safe, affordable, quality service to our customers, protect and preserve the environment, while maintaining or exceeding all Federal and State regulations “

The Hutchinson Wastewater Facility was placed in service in 1988 and is classified as a ‘Class A’ facility.

In 2008 a major expansion was completed to accommodate community growth and industrial expansion. Designed to treat an average 3.67 million gallons per day (MGD) of wastewater, the facility will meet the wastewater treatment needs of the city through the year of 2028. There are 13 lift stations and over 75 miles of gravity sanitary sewer lines throughout Hutchinson. The wastewater treatment facility continually undergoes changes as new technologies and ever more stringent state and federal environmental regulations come into place. The treatment facility has several features, which allow it to meet Hutchinson’s specific needs for variable flows and operational flexibility. Biological and Membrane Bioreactor (MBR) processes are used to remove impurities from the wastewater and achieve a level of treatment well above that which is mandated by the Minnesota Pollution Control Agency (MPCA).

The Facility has a staff of six people that include: Wastewater Supervisor, Operator, Laboratory Technician, Administrative/Lab Assistant, and two Maintenance personnel.

View Monthly Water Base and Usage Rates

Contact us prior to calling your plumber if you are experiencing issues with your sanitary sewer service or your sewer backs up. Collection System personnel will check to see if the city section of the sewer collection system is flowing readily and free from obstruction.

If you have an emergency after 3:30 pm weekdays, you may call (320) 587-2242 (Police Dept.) to report an issue.

Flushables - NOT!

The past few years have seen the introduction of more and more disposable wipe products for a variety of household uses. Many of these products are labeled as not only disposable, but also flushable.

While marketed as convenience items, these products may potentially become a huge inconvenience because they may clog not only the sewer on your property, but also cause blockages and backup problems in Hutchinson’s public sewer system and pump stations.
To understand how these wipes can become a problem, it’s important to know how the sewer system works. Every home has a sewer connection that runs from the home to the public sewer system. This sewer service line is the responsibility of the homeowner to maintain so there are no backups of wastewater into the home. From there, the sewage moves into larger collector lines, and pump stations help lift the wastewater across different elevations in the sewer system.

Why are household wipes a problem? Unlike toilet paper, these products don’t break down once they are flushed. They can then cause blockages in your home sewer lines, especially in older pipelines that may have already existing grease, roots or other obstructions, resulting in the backup of sewage into the home. A repair of the service line can leave the homeowner with a nasty repair bill—often not covered by homeowners’ insurance—and an even nastier clean up.

On a larger scale, when these products make their way into the public sewer system, they collect together and cause clogs in the collector lines and get tangled in lift pumps. When pump stations are clogged, they stop working and require cleaning and repair— or even replacement—in order to get the sewage moving again.

Avoid a nasty cleanup in your home and help protect the city’s sewer system by never flushing any consumer item that is not toilet paper into the sewer system, regardless of what the packaging promises. Put these items in the trash instead:

Diapers

Disinfecting wipes or baby wipes

Cotton swabs & cotton balls

Toilet cleaning pads

Mop refills

Tissues & paper towels

Moist towelettes

Feminine hygiene products

Dental floss

Clumping cat litter

Medicines

Rags

Oil or grease

Not sure what should or shouldn’t be flushed? Remember this easy reminder: if it’s not toilet paper, and if you didn’t eat it or drink it first, it shouldn’t go in the toilet. When in doubt, don’t flush! For more information, contact Hutchinson Wastewater Department at (320) 234-4233

Wastewater collected from the city is pumped to screening and grit removal systems to remove plastics, rags, sand, and other larger objects in the raw wastewater that could damage the process equipment. During the latest expansion new rotary fine screens and a vortex grit chamber were added to remove finer screenings and grit before being sent to the more sensitive MBR process. Influent flows are currently split in the preliminary treatment building and sent to the two separate treatment trains. Two-thirds of the flow is sent to the oxidation ditch/final clarifier process and the remaining flow is directed to the newer MBR process. The MBR system also eliminated the need to add additional clarifiers for separating the solids from the wastewater, as the spaghetti like membranes filter out virtually all solids, bacteria, and viruses.

Equalization Basin (EQ)

During periods that exceed the maximum wet weather flow design of 9.62 MGD, the excess influent can be diverted to the flow equalization basin. Lined with high-density polyethylene plastic, this basin serves as a temporary storage reservoir for as much as two million gallons of wastewater. After a storm has passed, the wastewater can then be drawn from the basin for treatment as plant capacity becomes available.

Biological Treatment

Oxygen is added to the wastewater in the two-oxidation ditches to help microorganisms consume organic wastes. There are two extended aeration units (each 377 feet long, 67 feet wide, and 12 feet deep) each containing 2.16 million gallons of wastewater. These are the largest municipal oxidation ditches of this type in the Midwest. Each is equipped with six rotating surface aerators and two aerating mixer units to mix the wastewater with the microbiology and to induce oxygen into the mixture. A more concentrated microbe/wastewater mixture is aerated in two separate aeration tanks before being transferred into the membrane tanks of the MBR process. Once in the membrane tanks, the water is continuously aerated to achieve optimum mixing and to reduce fouling of the membranes. A chemical process for phosphorus removal was also added during the expansion. The plant can remove greater than 90 percent of phosphorus that was previously discharged to the river.

Disinfection

Before discharging the water to the South Fork of the Crow River, it is sent through an ultraviolet

Ultra-Violet Bulb Racks for Disinfection

(UV) disinfection system where UV light is used to eliminate any remaining bacteria. To reduce the safety and security concerns associated with gaseous chlorine, the old chlorine disinfection system was removed and replaced with UV disinfection. The water that is filtered through the membrane strands of the MBR is so clean that it needs no additional UV disinfection before being discharged to the receiving stream.

Bio-Solids Handling and Dryer Facility

The biological process of treating wastewater uses microbiologic organisms to consume the waste and nutrients in the water. As these organisms consume materials in the wastewater, they exude energy by multiplying, or simply dividing, as is the case with the single celled bacteria. Excess activated sludge separated from the wastewater during the treatment process is pumped to one of two storage tanks for eventual dewatering. The two large sludge presses are used to obtain sludge cake suitable for fertilizing farmlands as a means of disposal. The City reserves approximately 700 acres of farm land for the application of biosolids.

The Bio-Solids Dryer Facility is another City initiative to improve efficiency while serving the growing needs of Hutchinson residents and businesses. The goal of the facility is to enhance bio-solids processing and provide the community with a “Class A” bio-solids to meet stringent federal standards and reduce disposal costs. Future additions to the facility could possibly improve the end product from a soils enhancing material to a marketable fertilizer for residential, commercial and agricultural use.

Bio-Solids Belt Dewatering Presses

Gas Fired Bio-Solids Dryer

Planning for the Future

The south area trunk sanitary sewer, constructed in 2002 provides Hutchinson with efficient, long-term service to the growing southwest sector of the community, including the T.H. 15 commercial corridor, as well as residential development in the area. The facility will also provide service to the T.H. 22 bypass area in the southeast area of the city.

The facilities include:

Lift station near the H.A.T.S. facility

Crossing of the South Fork of the Crow River to Jefferson Street

Sewer extension to the commercial area along T.H. 15

Sewer extension to the T.H. 22 bypass corridor

Final Effluent from MBR – Suitable for reuse as treatment plant process water.

The lift station is designed to accommodate the ultimate flows from the proposed service area, but will initially include pumping equipment to handle the flows for the first years of operation. Future pump additions/upgrades are sized to minimize capital costs and will occur as development continues.